Thomas Guilderson
Dados Biográficos
| ID | 5597067 |
|---|---|
| NOME | Thomas Guilderson |
| PRENOMES | Thomas |
| SOBRENOME | Guilderson |
| ASSINATURA | GUILDERSON T |
| AFILIAÇÕES | Lawrence Livermore National Laboratory |
| VERIFICADO | Não |
| TOTAL DE OBRAS | 5 |
| TOTAL DE CITAÇÕES | 11 |
| TOTAL COMO AUTOR | 5 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 2001 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2013 |
| ÍNDICE H | 2 |
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Extension of the Southern Hemisphere Atmospheric Radiocarbon Curve, 2120–850 Years BP
Decadal samples of dendrochronologically dated pine ( Lagorostrobos franklinii ) from the Stanley River basin, Tasmania, have been radiocarbon dated between 2120–850 yr BP. This data set overlaps and extends the current Southern Hemisphere record, which covers the period 110–995 yr BP. There is good agreement between the 2 records between 995–850 yr BP, between sample replicates and with consensus values for standards. As in the younger data set,…
Climate and vegetation history from a 14,000-year peatland record, Kenai Peninsula, Alaska
Analysis of pollen, spores, macrofossils, and lithology of an AMS 14 C-dated core from a subarctic fen on the Kenai Peninsula, Alaska reveals changes in vegetation and climate beginning 14,200 cal yr BP. Betula expansion and contraction of herb tundra vegetation characterize the Younger Dryas on the Kenai, suggesting increased winter snowfall concurrent with cool, sunny summers. Remarkable Polypodiaceae (fern) abundance between 11,500 and 8500 ca…
Challenges in Radiocarbon Dating Organic Carbon in Opal-Rich Marine Sediments
We explored the reliability of radiocarbon ages obtained on organic carbon phases in opal-rich Southern Ocean sediments. Paired biogenic carbonate and total organic carbon (TOC) 14 C analyses for three Southern Ocean cores showed that the TOC ages were systematically younger than the carbonate ages. Carbonate ages were consistent with oxygen isotopic and bio-stratigraphy, indicating error in TOC ages that could be explained by 5–24% of modern car…
Solar Forcing of Drought Frequency in the Maya Lowlands
We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records …
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Extension of the Southern Hemisphere Atmospheric Radiocarbon Curve, 2120–850 Years BP
Decadal samples of dendrochronologically dated pine ( Lagorostrobos franklinii ) from the Stanley River basin, Tasmania, have been radiocarbon dated between 2120–850 yr BP. This data set overlaps and extends the current Southern Hemisphere record, which covers the period 110–995 yr BP. There is good agreement between the 2 records between 995–850 yr BP, between sample replicates and with consensus values for standards. As in the younger data set,…
Challenges in Radiocarbon Dating Organic Carbon in Opal-Rich Marine Sediments
We explored the reliability of radiocarbon ages obtained on organic carbon phases in opal-rich Southern Ocean sediments. Paired biogenic carbonate and total organic carbon (TOC) 14 C analyses for three Southern Ocean cores showed that the TOC ages were systematically younger than the carbonate ages. Carbonate ages were consistent with oxygen isotopic and bio-stratigraphy, indicating error in TOC ages that could be explained by 5–24% of modern car…
Solar Forcing of Drought Frequency in the Maya Lowlands
We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records …
Challenges in Radiocarbon Dating Organic Carbon in Opal-Rich Marine Sediments
We explored the reliability of radiocarbon ages obtained on organic carbon phases in opal-rich Southern Ocean sediments. Paired biogenic carbonate and total organic carbon (TOC) 14 C analyses for three Southern Ocean cores showed that the TOC ages were systematically younger than the carbonate ages. Carbonate ages were consistent with oxygen isotopic and bio-stratigraphy, indicating error in TOC ages that could be explained by 5–24% of modern car…
Climate and vegetation history from a 14,000-year peatland record, Kenai Peninsula, Alaska
Analysis of pollen, spores, macrofossils, and lithology of an AMS 14 C-dated core from a subarctic fen on the Kenai Peninsula, Alaska reveals changes in vegetation and climate beginning 14,200 cal yr BP. Betula expansion and contraction of herb tundra vegetation characterize the Younger Dryas on the Kenai, suggesting increased winter snowfall concurrent with cool, sunny summers. Remarkable Polypodiaceae (fern) abundance between 11,500 and 8500 ca…
Extension of the Southern Hemisphere Atmospheric Radiocarbon Curve, 2120–850 Years BP
Decadal samples of dendrochronologically dated pine ( Lagorostrobos franklinii ) from the Stanley River basin, Tasmania, have been radiocarbon dated between 2120–850 yr BP. This data set overlaps and extends the current Southern Hemisphere record, which covers the period 110–995 yr BP. There is good agreement between the 2 records between 995–850 yr BP, between sample replicates and with consensus values for standards. As in the younger data set,…
Initial Results of an Intercomparison of AMS-Based Atmospheric 14 CO 2 Measurements
This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ 14 CO 2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ 14 CO 2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participa…
Geography (4 obras) · Geology and Paleoclimatology Research (4 obras) · Climatology (3 obras) · Geology (3 obras) · Physical geography (3 obras) · Archaeology and ancient environmental studies (2 obras) · Chemistry (2 obras) · Climate change (2 obras) · Ecology (2 obras) · Environmental Science (2 obras)